This disclosure generally relates to systems and methods for avoiding collisions during ground maneuvering by an aircraft.
As airplanes get larger, the distance between the main landing gear and nose landing gear (i.e., wheelbase and distance between each main landing gear (track)) becomes greater. As a result, turning maneuvers require more space. Because most airports were constructed to handle smaller, more maneuverable airplanes with shorter wheelbases and tracks, large airplane maneuvering becomes even more difficult. The restricted widths of the runways and taxiways, coupled with greater airport congestion, have made it progressively more difficult for pilots of large commercial airplanes to make tight maneuvers. Maneuvering large airplanes is difficult because of a lack of feedback to the pilots about relative positioning of the landing gear on the ground. The lack of feedback occurs because an airplane's landing gears are located beneath the fuselage or wings. Accurate knowledge of the location of landing gear, specifically the tires and wheels of the landing gear, is particularly important when maneuvering in tight spaces at crowded airports. A pilot's ability to see runway and taxiway edges, ground service vehicles and potential obstructions is also very limited in large airplanes. Large airplanes with long wheel bases and wide main gear track also face challenges in other types of ground maneuvers such as gate entry maneuvers and runway or turnpad U-turn maneuvers.
In the aviation industry today, the number of dollars lost to damage due to ground collision is significant. Not only do airlines have to repair the damage on one or more aircraft, they need to compensate passengers for schedule disruption, fly in other airplanes, and have their airplane out of service while the damage is repaired. These are costly events. Airport traffic levels are predicted to increase at a rate faster than airports are predicted to grow. Furthermore, the production of larger aircraft, including aircraft with a folding wingtip system, may present significant challenges for the future airport operating environment.
Existing solutions include a pilot's own visual judgment, a ground maneuvering camera system mounted on the aircraft, or dedicated wing walkers shepherding the airplane out of the gate/terminal.
In many instances a pilot relies on only his/her spatial judgment when attempting to navigate aircraft throughout an airport environment. Pilots are trained to maintain the centerline of taxiways, which should provide clearance, but is not guaranteed if there are other obstacles present. Some airplanes do not offer visibility of the wingtips from the vantage point of the flight deck. Low-visibility situations complicate this judgment task.
In other instances some airports provide airport personnel called wing-walkers to help guide the aircraft with assurance that there are no threatening obstacles to the wings. However, wing-walkers are not always available and certainly are not available all the way between the active runway and the ramp area.
Many aircraft today have an external camera system that is designed to aid the pilot in ground maneuvering operations. There are two primary functions for this type of system: help the pilot maintain the gear of the aircraft on the pavement and obstacle collision avoidance. An external camera system may show views of the wingtips, which allows pilots to monitor the position of each wingtip relative to obstacles within close proximity to mitigate wingtip collisions in either folded or extended positions. However, there may be a problem of perspective depending on where the camera is situated. More specifically, if a camera is installed on the empennage section of the aircraft and shows views of the wingtip, a significant off-axis distance exists between the two and makes it very difficult to judge the position of the wingtip relative to the ground or any obstacles in the vicinity of the wingtip.
Improved means and methods for providing guidance aids to a pilot for ground obstacle avoidance, particularly wingtip clearance, are wanted.